Police in Beijing are seeking information on at least eight suspects and five licence plates, the South China Morning Post has learnt on Tuesday. While most of the suspects appear to be Uygurs, one man bears an ethnic Han name.

The request for information circulated among Beijing hotels by police on Tuesday is believed to be linked to the fatal car crash in Tiananmen Square on Monday that killed five, including the three people in the vehicle.

There has been no official word on whether the incident was an accident or an attack. A source who has ties to the leadership, speaking on condition of anonymity, said it was the latter. "The jeep knocked down barricades and rammed into pedestrians. The three men had no plans to flee from the scene," the source said.

Police are still investigating and have yet to determine the identities of the three people in the vehicle, according to sources. Beijing police late on Monday asked hotels for information on two suspects from the restive far western region of Xinjiang in connection with a “major incident”.

Five people died and 38 were injured in the car crash when a light-coloured SUV rammed through barricades in front of Tiananmen Square’s gate tower and burst into flames on Monday. The area below late Chairman Mao Zedong’s portrait was quickly closed off and smoke could be seen rising behind an improvised barricade.

One eyewitness, who asked not to be identified due to the incident’s sensitive nature, said she saw the vehicle knock down three or four people, and that it had a white banner with black lettering on it streaming from the back.

On Tuesday, the Global Times, a Communist Party-run paper, said in its English-language version that police had linked the incident to suspects from Xinjiang. The Chinese language version did not mention Xinjiang.

Hotels were asked on Monday to provide information on the two suspects and the licence plates “to prevent […] further crimes.”

The notice on Tuesday reflects an expanded investigation. Police are looking for information on eight suspects, most of whom come from Xinjiang and were born in the 1980s. The one who carries the ethnic Han name, Liu Ke, is said to be from Sichuan province.

The Beijing police press office and the department that issued the first notice seeking information on Uygur suspects declined to comment. Chinese Foreign Ministry spokeswoman Hua Chunying, asked whether the government believed the incident was a terror attack, repeated a previous statement on Tuesday saying that the incident was being investigated.

Ilham Tohti, a prominent Uygur intellectual, cautioned against using the Tiananmen incident to stigmatise the ethnic group or imposing tighter controls in the region, according to an article on his web portal Uighurbiz.net.

It cited him as saying that, without evidence to justify the claims, it should not be described as a terrorist incident by Uygurs. He added, however, that extreme methods by Uygurs could not be ruled out.

Alim A Seytoff, President of the Uygur American Association, said he did not believe Uygurs were involved in the attack. “Usually the Chinese government is quick to point fingers at the Uygur people,” he said. “We learned there are arrest warrants for some Uygurs and we were surprised because it’s impossible for Uygurs […] to pull off something like that.”

Police have arrested at least 140 people in Xinjiang in recent months for allegedly spreading jihad, and killed 22 Uygurs in August in an “anti-terrorism” operation, according to state media and exiled sources.

Video: Several dead, dozens injured in Tiananmen Square car crash

A man from Guangdong and a woman from the Philippines died along with the three people in the SUV. The Philippines embassy in Beijing is yet to reply to requests for comment.

Censors on Monday rushed to delete comments on Chinese social media, allowing almost exclusively Beijing police and Xinhua updates to circulate online.

China Central Television’s nationally syndicated midnight news broadcast said the Communist Party’s central leadership and the ministry of public security were paying close attention to the incident and promised an “all-out effort to find the truth”.

Beijing newspapers on Tuesday carried the official Xinhua news agency statement, which did not provide any information on the background of the SUV’s driver or its two passengers.

The Chinese language version of the Global Times carried a commentary which argued that incidents at Tiananmen Square – the highly symbolic square where Mao Zedong declared the founding of the People’s Republic in 1949 and where troops violently cracked down on protesters calling for democracy in 1989 – “cannot be politicised”.